The Benelli® M4 Tactical shotgun has been battle-proven for reliability around the world by the U.S. Marine Corps since 1998. The Benelli M4 H2O semi-auto shotgun is the same M4 Tactical, enhanced with a Titanium Cerakote® finish for increased corrosion resistance and durability. The barrel, receiver, magazine tube, bolt and many internal parts are coated with either titanium or black Cerakote. The M4 operates by a unique, Auto-Regulating Gas-Operated (A.R.G.O.) system, featuring dual stainless steel, self-cleaning, pistons that bear directly on the bolt assembly. Benelli's ARGO mechanism eliminates the more complicated linkages and heavier parts of other semi-auto shotgun designs to produce a relatively simple and robust action. The auto-regulating gas system is designed to handle everything from field loads to hard-hitting 3" buckshot without the need of adjustments. The Benelli M4 H2O Tactical Shotgun comes with a pistol-grip synthetic buttstock, made to withstand any environment. The pistol-grip is made from a rubber/poly blend and the stock features a sturdy recoil pad, that together with the gas operation, cut recoil and muzzle lift considerably, allowing the shooter to stay on target and deliver rapid follow-up shots. An under-barrel sling point at the front of the handguard and one on each side of the stock facilitate ambidextrous sling attachment. The Benelli M4 Tactical Shotgun comes with a fully adjustable LPA ghost ring rear sight and a white dot front blade inside protective ears for quick target acquisition. A 5.25" Picatinny rail allows user to mount additional scopes and optical sights. The Benelli M4 H2O is an ideal personal defense shotgun to carry in marine environments, or a rugged, low-maintenance, all-purpose shotgun.